Cannabinoid was discovered as the main active substance contained in marijuana in 1960 and found to exhibit an activity in the central nervous system (illusion, euphoria, sensory confusion of time and space) and in the peripheral cell system (immunosuppressive activity, anti-inflammatory activity, analgesic activity).
After that, anandamide and 2-arachidonoylglycerol produced from arachidonic acid-containing phospholipids were discovered as endogenous agonists to the cannabinoid receptor. These endogenous agonists are known to exhibit an activity to the central nervous system and an activity to the peripheral cell system. It is disclosed in Hypertension (1997) 29, 1204-1210 that anandamide exhibits an activity to the cardiovascular system.
A cannabinoid type 1 receptor discovered in 1990 was found to distribute in the central nervous system such as the brain. Agonists to this receptor were found to suppress the release of neurotransmitters to cause central actions such as illusion. A cannabinoid type 2 receptor discovered in 1993 was found to distribute in immune tissues such as the spleen. Agonists to this receptor were found to suppress an activation of immunocyte or inflammatory cells to exhibit an immunosuppressive activity, an anti-inflammatory activity and an analgesic activity (Nature, 1993, 365, 61-65).
Therefore, agonists to the cannabinoid type 2 receptor are expected as immunosuppressive agents, anti-inflammatory agents, and analgesic agents (Nature, 1998, 349, 277-281).
Known as compounds having an agonistic activity to the cannabinoid type 2 receptor are isoindolynone derivatives (WO97/29079 and WO99/02499), pyrazole derivatives (WO98/41519) and the like.
Furthermore, J. Pharmacol. Exp. Ther., 2001, 296, 420-425 discloses that compounds having a binding activity (an agonistic activity and/or an antagonistic activity) to the cannabinoid type 2 receptor exhibit anti-inflammatory effect.
On the other hand, Japanese Patent Publications (Kokai 1986-65894, Kokai 1987-29594) disclose that organophosphorus compounds having a 2-imino-1,3-thiazine skelton are useful as insecticides.
Furthermore, WO00/42031 discloses that compounds resembling the compound of the present invention have a binding activity to the progesterone receptor.
However, it is not known that 2-imino-1,3-thiazine derivatives have a binding activity (an antagonistic activity and/or agonistic activity) to the cannabinoid type 2 receptor.